#include<stdio.h>
#include<math.h>
double fact(int);
double fact(int n)
{
	if (n == 0)
		return 1.0;
	return(n * fact(n - 1));


}
int main(void)
{
	int number;
	double max;
	scanf_s("%d", &number);
	max = fact(number);
	printf("the max is %lf", max);







}